Nitride semiconductors having high dielectric breakdown strength are expected to be applied to semiconductor devices for power electronics, high-frequency power semiconductor devices, or the like. However, when a high voltage is applied, a phenomenon such as current collapse occurs. When current collapse occurs, on-resistance increases and a drain current significantly decreases. This phenomenon is known to degrade characteristics of semiconductor devices.
In order to implement high-performance nitride-based semiconductor devices, it is desirable to suppress current collapse.